Re: php_stream_read(...) may return less than expected

On 12/03/15 14:28, Umberto Salsi wrote: > Hi all, > I'm not a PHP internals developer, but this might be a bug spread here and > there in the source. This coding pattern: > > if(php_stream_read(..., n) != n){ > php_error_docref(NULL TSRMLS_CC, E_SOMETHING, "Read error!"); > > seems wrong to me because there might be streams that returns less than > n bytes at once. When exactly n bytes are expected, not more not less, > a function similar to this one should be used instead: > > int php_stream_read_fully(..., int n){ > continue calling php_stream_read() until exactly n bytes are > collected, or a premature EOF, or I/O error > } > > I ran into this issue passing a custom stream to getimagesize(): > > getimagesize("myprotocol://"); > > where myprotocol:// may, in some situations, return less bytes than > expected (see the http://php.net/manual/en/class.streamwrapper.php^°´ > ¯aÄð×ì ¨·Âw > wrapper class, stream_read() method). Looking at the implementation of > this function in ext/standard/image.c, I just found the pattern above. > If this is really a bug, many other functions might be affected. Why does your stream behave non-blocking by default? Unless explicitly stated, those callees probably expect a blocking stream. -- Regards, Mike